Hydrotherapy is one of the oldest types of health treatments in existence today.  Hydrotherapy works because of two properties inherent in water: temperate and buoyancy.  Water is an excellent substance with which to carry temperature.  It can retain heat in a form that can easily be applied to the body.  These temperatures then affect the ways in which the body works.  In particular, temperature helps to aid in dilation and constriction of blood vessels.  This change in the blood vessels allows for improved circulation, better waste removal, and faster healing